Synthesis and nanoimprinting of high refractive index and highly transparent polythioethers based on thiol-ene click chemistry

This work demonstrates the UV nanoimprinting lithography (UV-NIL) of high refractive index and highly transparent polythioethers based on thiol-ene click chemistry. Herein, 9,9-bis(3-mercaptopropylphenylether)fluorene (BMPF) is designed as a new thiol monomer with a high refractive index, high transparency, and good processability for UV-NIL. Colorless polythioethers are synthesized from BMPF and ene monomers under mild thiol-ene click reaction conditions. Excellent transmittance (96%) of 400 nm light is observed in all the polymer films and high refractive index values of 1.5972–1.6382 are attained. UV-NIL using thiol-ene photopolymerization affords polymer nanoimprinting patterns with various features on the order of 100–500 nm without any fractures. To the best of our knowledge, this is the first report on UV-NIL of high refractive index and highly transparent polymers. Through proper monomer and polymer design, novel polythioethers with suitable glass transition temperature (T _g) values are developed with high refractive index, high transparency, and good UV-NIL processability. Furthermore, UV-NIL based on thiol-ene click chemistry is accomplished at the nanoscale. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2175–2182     

Fluorene pendant-functionalization of poly(N-vinylcarbazole) as deep-blue fluorescent and host materials for polymer light-emitting diodes

π-Electron coupling of pendant conjugated segment in π-stacked semiconducting polymers always causes the formation of defect trapped sites and further quenched high-band excitons, which is harmful to the performance and stability of deep-blue polymer light-emitting diodes (PLEDs). Herein, considerate of “defect” carbazole (Cz) electromers in poly(N-vinylcarbazole) (PVK), a series of fluorene units are introduced into pendant segments (PVCz-DMeF, PVCz-FMeNPh and PVCz-DFMeNPh) to suppress the strong π-electron coupling of pendant Cz units and enhance radiative transition toward fabricating sable PLEDs. Compared to PVCz-FMeNPh and PVCz-DFMeNPh, PVCz-DMeF spin-coated films show a relatively efficient deep-blue emission, completely similar to its single pendant chromophore, confirmed an extremely weak charge-transfer and electron coupling between adjacent pendant segments. Therefore, PLEDs based on PVCz-DMeF present stable and deep-blue emission with a high color purity (0.17, 0.08), associated with extremely weak defect emission at 600∼700 nm (induced by carbazole electromers). Finally, PLEDs based on PVCz-DMeF/F8BT blended films (1:1) also present the high maximum luminance (L_max) of 6261 cd/m² and current efficiency (CE_max) of 2.03 cd/A, confirmed slightly trapped sites formation. Therefore, precisely control the arrangement and packing model of pendant units in π-stacked polymer is an essential prerequisite for building efficient and stable emitter for optoelectronic devices.     

Mussel-inspired chemistry for robust and surface-modifiable multilayer films

In this article, we report a bioinspired approach to preparing stable, functional multilayer films by the integration of mussel-inspired catechol oxidative chemistry into a layer-by-layer (LbL) assembly. A polyanion of poly(acrylic acid-g-dopamine) (PAA-dopamine) bearing catechol groups, a mussel adhesive protein-mimetic polymer, was synthesized as the building block for LbL assembly with poly(allylamine hydrochloride) (PAH). The oxidization of the incorporated catechol group under mild oxidative condition yields o-quinone, which exhibits high reactivity with amine and catechol, thus endowing the chemical covalence and retaining the assembled morphology of multilayer films. The cross-linked films showed excellent stability even in extremely acidic, basic, and highly concentrated aqueous salt solutions. The efficient chemical cross-linking allows for the production of intact free-standing films without using a sacrificial layer. Moreover, thiol-modified multilayer films with good stability were exploited by a combination of thiols-catechol addition and then oxidative cross-linking. The outstanding stability under harsh conditions and the facile functionalization of the PAA-dopamine/PAH multilayer films make them attractive for barriers, separation, and biomedical devices.     

聚丙烯酸芴酯的电化学氧化交联反应及其表征

合成了侧链带有芴的聚丙烯酸芴酯(PFM),在含40%三氟化硼乙醚的二氯甲烷混合电解质溶液中,直接阳极氧化PFM获得了自支撑交联网状的聚(聚丙烯酸芴酯)(CPFM)薄膜.通过UV-Vis、FTIR和1H-NMR对CPFM结构进行了表征.荧光光谱表明得到的聚合物薄膜CPFM在415nm附近处具有强的荧光发射峰,表明聚丙烯酸结构的引入没有影响聚芴的蓝色发光性能并有利于提高聚合物薄膜的力学性能.TGA表明得到的CPFM薄膜具有良好的热稳定性。     

"Thiol-ene" click chemistry: a facile and versatile route for the functionalization of porous polymer monoliths

The preparation of porous polymer monoliths with dodecyl and zwitterionic functionalities via the "thiol-ene" click chemistry of thiol-containing monoliths with both hydrophobic and polar methacrylate "ene" monomers has been demonstrated. Selected separations confirmed the excellent potential of these monoliths in chromatography.     

9位芳香基取代超支化聚芴的合成与表征

以2,7-二溴芴酮为起始原料,在芴的9位引入芳香取代基代替传统的烷基取代基,增加9位的稳定性,并用AB+AB2的方法,用新单体合成了不同支化度的超支化聚合物,新合成的超支化聚合物具有良好的热稳定性和发光稳定性.聚合物的热分解温度都在400℃以上;聚合物的薄膜在空气中于200℃加热2 h后没有出现绿光发射带,发光稳定性和烷基聚芴相比得到明显的提高.DSC结果显示,线性聚合物在170℃时有玻璃化转变,超支化聚合物在300℃以内没有明显的相转变,保持一种稳定的无定形态,更有利于提高材料的发光效率.     

Synthesis and characterization of fluorene‐based copolymers containing benzothiadiazole derivative for light‐emitting diodes applications

Five new thermally robust electroluminescent fluorene‐based conjugated copolymers, including poly[2,7‐(9,9‐dioctylfluorene)‐co‐4,7‐{5,6‐bis(3,7‐dimethyloctyloxymethyl)‐2,1,3‐(benzothiadiazole)}] ( PFO‐P2C₁₀BT ) were synthesized and used to fabricate the efficient polymer light‐emitting diodes (PLEDs). The glass transition temperatures of the polymers were found to be higher than that of poly(9,9‐dialkylfluorenes) and are in the range 113–165 °C. We fabricated PLEDs in indium‐tin oxide/PEDOT/light‐emitting polymer/cathode configurations using either double‐layer LiF/Al or triple‐layer Alq₃/LiF/Al cathode structures. The new copolymers were found to have emission colors that vary from greenish blue (491 nm) to green (543 nm) depending on the copolymer composition. The maximum brightness and luminance efficiency of these PLEDs were found to be up to 5347 cd/m² and 1.51 cd/A at 10 V, respectively. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6762–6769, 2008     

Vinyl functionalized silica hybrid monolith-based trypsin microreactor for on line digestion and separation via thiol-ene "click" strategy

A novel thiol-ene "click" strategy for the preparation of monolithic trypsin microreactor was proposed. The hybrid organic-inorganic monolithic capillary column with ene-functionality was fabricated by sol-gel process using tetramethoxysilane (TMOS) and γ-methacryloxypropyltrimethoxysilane (γ-MAPS) as precursors. The disulfide bonds of trypsin were reduced to form free thiol groups. Then the trypsin containing free thiol groups was attached on the γ-MAPS hybrid monolithic column with ene-functionality via thiol-ene click chemistry to form a trypsin microreactor. The activity of the trypsin microreactor was characterized by detecting the substrate (Nα-p-tosyl-L-arginine methyl ester hydrochloride, TAME) and the product (Nα-p-tosyl-L-arginine, TA) with on-line capillary zone electrophoresis. After investigating various synthesizing conditions, it was found that the microreactor with poly(N,N'-methylenebisacrylamide) as spacer can deliver the highest activity, yielding a rapid reaction rate. After repeatedly sampling and analyzing for 100 times, the monolithic trypsin microreactor still remained 87.5% of its initial activity. It was demonstrated that thiol-ene "click" strategy for the construction of enzyme microreactor is a promising method for the highly selective immobilization of proteins under mild conditions, especially enzymes with free thiol radicals.     

Poly[(mercaptopropyl)methylsiloxane](PMMS)-based antibacterial polymer coatings prepared by a two-step sequential thiol–ene click chemistry

Poly[(mercaptopropyl)methylsiloxane](PMMS)-based antibacterial polymer coatings have been prepared through a two-step sequential thiol–ene click chemistry utilizing 1-allyl-3-decylimidazolium bromide(ADIm) as antibacterial monomer and triallyl cyanurate(TAC) as the crosslinker. These films with different content of ADIm were characterized by thermogravimetric analysis(TGA), dynamic mechanical analysis(DMA) and pencil hardness. It was found that the mechanical and thermal properties of these films were largely influenced by the content of ADIm in the films. Films with imidazolium bromide groups displayed excellent antimicrobial activity against Staphylococcus aureus with 100% killing efficiency.     

Biocompatible "click" wafer bonding for microfluidic devices

We introduce a novel dry wafer bonding concept designed for permanent attachment of micromolded polymer structures to surface functionalized silicon substrates. The method, designed for simultaneous fabrication of many lab-on-chip devices, utilizes a chemically reactive polymer microfluidic structure, which rapidly bonds to a functionalized substrate via"click" chemistry reactions. The microfluidic structure consists of an off-stoichiometry thiol-ene (OSTE) polymer with a very high density of surface bound thiol groups and the substrate is a silicon wafer that has been functionalized with common bio-linker molecules. We demonstrate here void free, and low temperature (< 37 °C) bonding of a batch of OSTE microfluidic layers to a silane functionalized silicon wafer.     

基于Diels-Alder反应的可交联空穴传输材料的合成及其在聚合物发光二极管中的应用

设计合成了一种侧链含呋喃的可交联共轭聚合物空穴传输材料聚{2,7-[9,9-二(6-(2-呋喃甲氧基)己基)芴]-共-4,4′-(4″-丁基)三苯胺}(P1)和侧链含马来酰亚胺的共轭小分子交联剂N,N′-二[4-(6-马来酰亚氨基己基)苯基]-N,N′-二苯基联苯二胺(M1).基于呋喃和马来酰亚胺间Diels-Alder反应,P1和M1共混膜可在150°C下热处理快速交联形成具有优异抗溶剂性的薄膜,同时薄膜的光电性能可以通过控制P1和M1的共混比例进行有效调节.器件研究结果表明,基于P1+M1交联的薄膜表现出了优异的空穴传输、电子阻挡性质,应用于聚合物发光二极管时可有效避免由传统空穴传输材料聚3,4-亚乙二氧基噻吩/聚苯乙烯磺酸(PEDOT:PSS)作为单一界面层引起的发光淬灭现象,使相应器件性能得到大幅提升.当M1添加量为10%时,相关器件表现出了最佳的器件性能,器件的最大电流效率为9.0 cd A~(-1),最大亮度为35681 cd m~(-2),启亮电压为3.2 V.     

Hole injection/transport materials derived from Heck and sol-gel chemistry for application in solution-processed organic electronic devices

An organosilicate polymer, based on N,N'-diphenyl-N,N'-bis(4-((E)-2-(triethoxysilyl)vinyl)phenyl)biphenyl-4,4'-diamine (TEVS-TPD) with extended conjugation between the Si atom and the aromatic amine, was prepared under mild conditions via sequential Heck and sol-gel chemistry and used as an alternative to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the most widely used planarizing hole injection/transport layer in solution-processed organic electronic devices. Spin-coating TEVS-TPD polymer solutions yield defect-free, uniform, thin films with excellent adhesion to the ITO electrode. Upon thermal cross-linking at 180 °C, the cross-linked polymer exhibits excellent solvent resistance and electrochemical stability. Solution-processed organic light emitting diode (OLED) devices using iridium-based triplet emitting layers and cross-linked TEVS-TPD films as a hole injection/transport layer show significantly improved performance including lower leakage current, lower turn-on voltage, higher luminance, and stability at high current density, as compared to the control device prepared with PEDOT:PSS.     

Photoluminescent color tuning in fluorene derivative/copolymer composite films based on H-bonds

Reversible addition-fragmentation chain transfer (RAFT) polymerization is used to synthesize diblock and random copolymers of poly[(2-trifluoroethyl methacrylate)-co-(methacrylic acid)]. Copolymer films doped with fluorene derivatives comprised of pyridine groups exhibit reversible photoluminescent (PL) color tuning by adjusting the location of fluorene derivatives in H-bonds or non-H-bonds environments. The composite films exhibit green and blue photoluminescence with and without effective H-bonding between the pyridine ring in the fluorene derivative and the carboxylic acid side group, respectively. At elevated temperatures, the H-bonded structure dissociates and the fluorene derivative migrates to the hydrophobic block in the diblock polymer, and they do not form H-bonds upon cooling. However, re-formation of H-bonds also occurs upon cooling random copolymers. Moreover, adjusting the annealing temperature and the solvent annealing reversibly tunes the PL color in the diblock copolymer composite films.     

Stimuli-responsive properties of N-isopropylacrylamide-based ultrathin hydrogel films prepared by photo-cross-linking

To develop stimuli-responsive ultrathin polymer films on a solid substrate, a novel photo-cross-linkable polymer with both temperature- and pH-responsive properties was prepared. The photoreactive 4-aminobenzophenone (BP) was introduced onto the side groups of poly(N-isopropylaclylamide-co-2-carboxyisopropylaclylamide) [poly(NIPAAm-co-CIPAAm)]. This copolymer was designed for highly random sequences of comonomers. After the formation of spin-coated polymer films on a solid substrate, UV-light irradiation started the cross-linking reaction. The spin-coating processes and stability of the polymer films were quantitatively monitored by a quartz crystal microbalance (QCM), and the thickness was estimated using an atomic force microscope (AFM). These measurements confirmed the formation of a very plain polymer film, and the film thickness was precisely controlled by the concentration of the polymer solution used for spin coating. Moreover, the obtained films showed a high stability due to the cross-liking reaction and UV irradiation. Cyclic voltammetry using potassium ferricyanide revealed that the ions could permeate the photo-cross-linked ultrathin polymer films. The permeability of the ultrathin hydrogel films was dramatically changed by varying the pH and temperature of the aqueous media. These observations suggest that the preparation of isopropylacrylamide-based stimuli-responsive ultrathin hydrogel films is possible.     

Electroluminescence of poly(N-vinylcarbazole) films: fluorescence, phosphorescence and electromers

We have studied the electroluminescence (EL) properties of pure poly(N-vinylcarbazole) (PVK) films. Three types of light emission in the EL spectrum were observed, attributed to fluorescence, phosphorescence and electromers, respectively. The observation of electrophosphorescence from PVK films at room temperature is very meaningful, indicating that PVK can produce a large number of triplet excitons under an electric field at room temperature. Our results demonstrate clearly the reason why PVK is an excellent host material for phosphorescent polymer light-emitting diodes (PLEDs).     

以膦酸酯聚芴作为阴极界面修饰层的高效聚合物红光电致发光器件

以膦酸酯聚芴为阴极界面修饰层, 高功函金属铝为阴极, 制备了一种高效聚合物红光电致发光器件. 通过X射线光电子能谱(XPS)的表征, 分析了经真空蒸镀沉积在膦酸酯聚芴表面的Al原子与下层的膦酸酯聚芴在有机物-金属界面处的作用情况, 结果表明, 在真空蒸镀金属Al的过程中, 在有机物-金属界面处形成了一种氧/铝复合物. 研究了这种氧/铝复合物对器件光电性能的影响, 结果表明, 氧/铝复合物的产生提高了阴极电子的注入, 使器件效率得到了很大提高. 与以Ca/Al为阴极的传统器件相比, 以膦酸酯聚芴/Al为阴极的聚合物电致发光器件的效率提高了75%, 达到7.0 cd/A.     

硫醇-烯/炔点击化学合成功能聚合物材料

点击化学具有反应条件温和、产率高、速率快、产物容易分离以及高度选择性等优点,成为国内外研究的热点之一。硫醇-烯/炔光化学反应作为新型高效的点击反应近年来备受关注,通过这种方法制备高性能及功能性聚合物材料也是新材料领域的前沿研究内容。本文综述了近年来硫醇-烯/炔点击化学在功能聚合物材料合成中的研究成果,详细介绍了硫醇-烯/炔点击化学的特点、优势及其反应机理,重点归纳了利用硫醇-烯/炔点击化学合成线型、超支化、交联等分子结构的功能聚合物材料的研究进展,并对由这种方法合成功能聚合物的单体特点、反应路线及产物应用进行了阐述,最后对硫醇-烯/炔点击化学的进一步应用前景做了展望。     

Synthesis,Photophysics, and Electroluminescence of Poly(dibenzofluorene)s

Summary: A series of soluble poly(dibenzofluorene) derivatives that contain dibenzo[a,g]fluorene, dibenzo[a,i]fluorene, and dibenzo[c,g]fluorene repeat units in the main chain have been synthesized, characterized, and explored as emissive materials in polymer light emitting diodes (PLEDs). These polymers possess higher glass transition temperatures (108–133 °C) than that of poly(2,7‐(9,9‐dialkyl)fluorene) (PFO). The photophysical and electrochemical properties of these polymers are affected by the steric hindrance effect. These polymers emit blue light in dilute solution (378–400 nm) and in the solid state (426–447 nm). As emissive materials in PLEDs, blue electroluminescence with a brightness of up to 3 130 cd · m⁻² is obtained from single‐layer diodes of P₂ with aluminum/barium in air.

The photophysical and electrochemical properties of these polymers are affected by the size effect.     

SYNTHESIS OF A HYPERBRANCHED POLY(AROYLARYLENE) CONTAINING TRIAZOLE AND FLUORENE FUNCTIONALITIES BY CLICK CHEMISTRY AND METAL-FREE, REGIOSELECTIVE POLYCYCLOTRIMERIZATION

A new bis(aroylacetylene) containing tfiazole and fluorene moieties is synthesized by click chemistry. Polycyclotrimerization of the monomer is catalyzed by piperidine in refluxed dioxane,furnishing a regioregular poly(aroylarylene) in a satisfactory yield.The hyperbranched structure of the polymer is characterized spectroscopically with satisfactory results.The polymer enjoys no metal detriment and is soluble in common organic solvents such as tetrahydrofuran (THF),chloroform,dichloromethane (DCM),and N...     

Surface modification of silicate glass using 3-(mercaptopropyl)trimethoxysilane for thiol-ene polymerization

A thiol-ene polymerization was accomplished on silicate glass slides to graft a series of homopolymers and copolymers using 3-(mercaptopropyl)trimethoxysilane (MTS) as both a silane coupling agent and initiator. MTS was initially covalently bonded to an acid cleaned glass surface via a classical sol-gel reaction. Poly(acrylic acid) (PAA), poly(acrylamide) (PAAm), poly(methyl acrylate) (PMA), poly(acrylamido-2-methyl-propanesulfonic acid) (PAMPS), and the copolymer poly(AA-co-AAm-co-MA-co-AMPS) were grafted from the thiol group of MTS. The surface chemistry of the MTS modified slides and polymer grafts was characterized with attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Surface texture was evaluated with tapping mode atomic force microscopy (TM-AFM). The Owens-Wendt-Kaelble (OWK) and Lifshitz-van der Waals acid-base (LW-AB) methods were used to evaluate surface energies by sessile drop contact angle method. The synthetic approach demonstrated a facile, rapid method for grafting to glass surfaces.